Washer drain overflowing

My daughter bought a house, an older one, and when the washer drains it overflows out of the drain line.
They have run the line and there is no blockage. I'm thinking its not vented properly. I haven't been to her house but am going in a couple of weeks. Is it possible to add a separate vent to just that line and what would be the best way to o it? Is my theory even valid or is there something else I need to be looking for?

Washer drain overflowing

bill when you get there you don't have to start opening up walls ...it could be just a clog...maybe needs to be snaked out ...can't imagine old owners living with that type of problem....let us know how we can help when you get there...ben sr

Washer drain overflowing

Thanks Ben. They are turning me into a grandpa around the tenth of next month so that's when I'm going. Gotta find something to do to get out of changing diapers. Doing it for my three was more then enough.

Washer drain overflowing

Quote:

Originally Posted by BillZ

Thanks Ben. They are turning me into a grandpa around the tenth of next month so that's when I'm going. Gotta find something to do to get out of changing diapers. Doing it for my three was more then enough.

congrats...my son still has only given me grand puppies..and alot of work on there home as well ...the 10th of next month is a long time to deal with that problem ..maybe your son or daughter can give us some pictures that we could help solve before that..ben sr

Washer drain overflowing

They've been running the drain into a sink. I didn't even know about it until last week. I trust her to take care of patients in the hospital and him to do whatever he does at the nuclear plant, but when he was explaining hydrostatic pressure and a bunch of other really technical engineering terminology I concluded I better take care of this myself. Ya just gotta trust me on this one.

Before I get too much grief, I know he's probably technically correct, but when I mentioned inadequate venting as a cause of this he had no idea drains in the house were even vented. The 'plumbing' he works with is a little different.

Washer drain overflowing

If its an older home it might have copper drain pipes. They might be joined together with boots and breeze clamps. Go down to crawlspace and have a look. If so just take a couple drain pipes apart see whats going on in them. This is what i did. Some stuff was in them. I just took it outside ran a hose threw it. Put it back no problems.

Washer drain overflowing

Quote:

Originally Posted by BillZ

Before I get too much grief, I know he's probably technically correct, but when I mentioned inadequate venting as a cause of this he had no idea drains in the house were even vented. The 'plumbing' he works with is a little different.

You got that right. I spent many years in the nuclear industry. If a nuclear plant is venting, there's a real problem.

Washer drain overflowing

Manufacturers don't care what size drain you have, how many bends or whether the line is vented. Their only concern is to have their machine pump the water faster than their competition.

I solved this problem years ago with an undersized drain that had a half dozen short radius 90s by restricting the discharge. So what if it takes a minute and a half to pump the 30 gallons of water rather than forty five seconds. And please don't tell me the pump will suffer and be ruined. It ain't going to happen because of the pump design.